Speaking at the Business in Sport and Leisure conference, Brailsford said: "We started Team Sky with a very clear policy, we were going to try to recruit the riders and the staff who hadn't had previous convictions for doping and, to the best of our knowledge, had no previous involvement in doping.

"It was important to stick with the policy but we have to go through some pain - some short-term pain, some medium-term pain, potentially and maybe even some performance pain - to get to where we want to be."